linux-stable/arch/x86
Kirill A. Shutemov 9cf3060640 x86/boot: Set CR0.NE early and keep it set during the boot
TDX guest requires CR0.NE to be set. Clearing the bit triggers #GP(0).

If CR0.NE is 0, the MS-DOS compatibility mode for handling floating-point
exceptions is selected. In this mode, the software exception handler for
floating-point exceptions is invoked externally using the processor’s
FERR#, INTR, and IGNNE# pins.

Using FERR# and IGNNE# to handle floating-point exception is deprecated.
CR0.NE=0 also limits newer processors to operate with one logical
processor active.

Kernel uses CR0_STATE constant to initialize CR0. It has NE bit set.
But during early boot kernel has more ad-hoc approach to setting bit
in the register. During some of this ad-hoc manipulation, CR0.NE is
cleared. This causes a #GP in TDX guests and makes it die in early boot.

Make CR0 initialization consistent, deriving the initial value of CR0
from CR0_STATE. Since CR0_STATE always has CR0.NE=1, this ensures that
CR0.NE is never 0 and avoids the #GP.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20220405232939.73860-23-kirill.shutemov@linux.intel.com
2022-04-07 08:27:53 -07:00
..
boot x86/boot: Set CR0.NE early and keep it set during the boot 2022-04-07 08:27:53 -07:00
coco x86/tdx: Wire up KVM hypercalls 2022-04-07 08:27:52 -07:00
configs x86/config: Make the x86 defconfigs a bit more usable 2022-03-27 20:58:35 +02:00
crypto This push fixes the following issues: 2022-03-31 11:17:39 -07:00
entry Kbuild updates for v5.18 2022-03-31 11:59:03 -07:00
events asm-generic updates for 5.18 2022-03-23 18:03:08 -07:00
hyperv hyperv-next for 5.17 2022-01-16 15:53:00 +02:00
ia32 audit/stable-5.16 PR 20211101 2021-11-01 21:17:39 -07:00
include x86/acpi/x86/boot: Add multiprocessor wake-up support 2022-04-07 08:27:53 -07:00
kernel x86/acpi/x86/boot: Add multiprocessor wake-up support 2022-04-07 08:27:53 -07:00
kvm * Only do MSR filtering for MSRs accessed by rdmsr/wrmsr 2022-04-02 12:09:02 -07:00
lib A set of x86 fixes and updates: 2022-04-03 12:15:47 -07:00
math-emu x86: Prepare asm files for straight-line-speculation 2021-12-08 12:25:37 +01:00
mm ptrace: Cleanups for v5.18 2022-03-28 17:29:53 -07:00
net Add support for Intel CET-IBT, available since Tigerlake (11th gen), which is a 2022-03-27 10:17:23 -07:00
pci PCI/sysfs: Find shadow ROM before static attribute initialization 2022-01-26 10:41:21 -06:00
platform objtool,efi: Update __efi64_thunk annotation 2022-03-15 10:32:32 +01:00
power x86: Prepare asm files for straight-line-speculation 2021-12-08 12:25:37 +01:00
purgatory x86/purgatory: Remove -nostdlib compiler flag 2021-12-30 14:13:06 +01:00
ras
realmode x86/boot: Set CR0.NE early and keep it set during the boot 2022-04-07 08:27:53 -07:00
tools x86/build: Use the proper name CONFIG_FW_LOADER 2021-12-29 22:20:38 +01:00
um Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2022-04-01 19:57:03 -07:00
video
virt/vmx/tdx x86/tdx: Provide common base for SEAMCALL and TDCALL C wrappers 2022-04-07 08:27:50 -07:00
xen xen: branch for v5.18-rc1 2022-03-28 14:32:39 -07:00
.gitignore
Kbuild x86/cc: Move arch/x86/{kernel/cc_platform.c => coco/core.c} 2022-02-23 18:25:58 +01:00
Kconfig x86/tdx: Exclude shared bit from __PHYSICAL_MASK 2022-04-07 08:27:51 -07:00
Kconfig.assembler
Kconfig.cpu x86/mmx_32: Remove X86_USE_3DNOW 2021-12-11 09:09:45 +01:00
Kconfig.debug
Makefile x86: Remove toolchain check for X32 ABI capability 2022-03-15 10:32:48 +01:00
Makefile.um
Makefile_32.cpu